Recuperative kiln.



R. D. PIKE.

RECUPERATIVE KILN. APPLICATIONYFILED JUNEI, I9I5.

Patented Dec. 5, 1916.

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R D. PIKE.

RECUPERATWE KILN.

APPLICATION FILED JUNE l, 1915.

' Patented Dec. 5, 1916.

4 SHEETS-SHEET 2.

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R. D. PIKE.

BECUPERATIVE KILN.

APPLICATION flLED IUNE I, 1915.

Patented Dec. 5, 1916.

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R. D. PIKE.

RECUPERATIVE KILN.

APPLICATION FILED mm: 1. I915. lfiUWfiUH.

Patented Dec. 5 1916. 4 SHEETS-SHEET 4 llllll'lll l llAil i m: NORRIS PETERS co" Pmmrunw" WASHINCION. n. c.

ROBERT D. PIKE, OF RICHMOND, CALIFORNIA.

RECUPERATIVE KILN.

memos.

Specification of Letters Patent.

Patented Dec. 5, 1916.

Application filed June 1, 1915. Serial N 0. 31,342.

To all whom it may concern:

Be it known that 1, ROBERT D. PIKE, a citizen of the United States, residing at Richmond, in the county of Contra Costa and State of California, have invented certain new and useful Improvements in Recuperative Kilns, of which the following is a specification.

The present invention relates to kilns generally for the burning of bricks, pottery and similar articles, but the same is more particularly designed and applicable for the burning of carbons and other articles requiring a high temperature, and resides more particularly in the adaptation of the beehive type of kiln for such purposes.

Heretofore the types of kilns commonly employed for the burning of carbons and other articles requiring high temperatures are those known in the art as continuous furnaces, the objection to which resides in the fact that the material cannot be treated as independent charges.

The object of the present invention is to render the bee-hive type of kiln, in which each charge may be independently treated, available for uses requiring relatively high temperatures, by increasing the thermal efficiency obtainable therein, and the invention consists essentially in the construction of a down-draft kiln having a recuperator associated therewith so as to form an integral portion thereof.

In order to comprehend the invention reference should be had to the accompanying sheets of drawings, wherein Figure 1 is a part sectional plan view of the improved kiln, showing the construction at different levels thereof. Fig. 2 is a sectional elevation along the line wa1 of Fig. 1. Fig. 3is a sectional elevation along the line 'y 2 of Fig. 1. Fig. 4 is a part sectional elevation along the irregular line za of Fig. 1. Fig. 5 is an elevation, enlarged, of a detail of the recuperator construction.

Throughout the drawings, the numeral 1 is used to designate the kiln, shown as a round or bee-hive kiln for reasons hereinafter set forth. Said kiln 1 is here represented as built upon the surface of the ground 2, and is formed with a plurality of horizontally disposed fire openings or ports 3, preferably set at equal intervals around its peripheral wall 4, said fire ports being provided with suitable fuel burners 5, and

temporary walls or fire-doors 6, and being further provided, adjacent to their inner ends, with baffle or deflector walls 7 so constructed as to direct the hot gases from the burners 5 upwardly against the domed interior 4 of the roof of the kiln.

Beneath the floor 8 of the kiln 1, and set largely below the ground level 2 is the recuperator 9, which is divided by the vertical central wall 10 into two substantially symmetrically disposed independent units 10 and 10 having a common outlet for the burned gases, said outlets consisting of the header 11 and the flue 12, connected with any suitably constructed chimney or stack, not shown herein.

The recuperator 9 comprises the lower wing walls .13, bridged across the header 11 by the arches 14, and upon these wing walls 13 are placed the vertical flues 15, constructed of stacks of hollow flanged tiles 16.

It will be seen by reference to Fig. 1 of the drawings, that the hollow tiles 16 are bridged across the lower wing walls 13, so that the vertical flues 15 communicate at their lower ends with the horizontally disposed flues 17 formed by the wing walls 13, Figs. 2 and 3 of the drawings, which flues in turn communicate with the header 11.

It will also be seen that the hollow tiles 16 forming the vertically disposed flues 15 are so placed relative to each other, that a series of channels 18 are formed between the said hollow tiles 16. These channels 18 are divided into a plurality of horizontal fiues 19, Figs. 2 and 3 of the drawings, by the horizontal walls 20. Said horizontal walls are shown in Fig. 5 of the drawings, as constructed of split bricks 21 resting upon the flanges 22 of the hollow tiles 16. Above the stacks of hollow tiles 16 are the upper wing walls 23, which are so disposed relative to to each other as to form a series of vertical flues 24, which said flues communicate with the vertical flues 15, Figs. 1 and 3 of the drawings. Upon the upper wing walls 23 rests the floor 8 of the kiln, said floor being constructed with vertical passages 25 which register with the flues 24 formed by the upper wing walls 23.

The recuperator, to secure the greatest thermal efliciency, is preferably rectangular in form, and divided, as before stated, by the wall 10 into two units 10 and 10 symmetrically disposed with respect to the vertical axis of the kiln. The said units 10 with; ba i rs? through the air .p rt

When the fires are started, the flames and and 10 are provided respectively with the air inlets 26 and 26 which are controlled by suitable dampers 27 and 27. The air inlet 26communicates through the chamber 28 with several of the lower tiers of horizontal flues 19, shown as three tiers in Fig. 2 of the drawings. At the opposite end of said recuperator unit'is the chamber 29,'Which allows the air, after passing through the three lowermost tiers of horizontal fines 19, as indicated by the arrows in Fig. 2 of the drawings, to reverse its direction and'fiow back throughthe next three tiers of horizontal flues 19 to" the chamber 30, where it is again reversed and passes through the uppermostjfour tiers of horizontal fiues 19 of the recuperator unitlO into the chamber 81. A complete horizontal annular flue 32 is constructed in-the base of the kiln wall, said annular flue 32 communicating with the final'recuperator chan'iber 31, as shown in Fig. 20f the drawings, and also communieating through the vertical passages 33 with the fire ports 3, in proximity totheburners 5, e The passages 33 are provided with damper-s84, operatablefand entirely removable through the air ports 35.

should be noted that the companion unit 1.0 of the recuperator has its air inlet at 26' vand therefore its outlet (not shown) into the annular fiue 32 is diametrically opposite to the outlet 31' of therecuperator unit 10. This symmetrical division of the re cuperator into independent units 10 and 10 is for the purpose of insuring .a free circulation of heated, air in the annular flue 32, so that each burner will receive an equal supply of air. Moreover, by placing the burne'rs at equal intervals in. the periphery of. the kiln, an even distribution of heat within the iln i se ur The recuperator, as before stated, is preferaloly rectangular in form, but the kiln 1, for structural reasonswell known in the art, is. circular, Moreover, the recuperator, to

secure the greatest possible thermal eiiiclency, is set immediately beneath the floor of' the' said kiln partly within the Walls thereof and partly belowithe ground level. When thus constructed there are employed l a lia' f nd 3 1.1 }4 6f the wings at the outlets of recuperator units,to secure a'free ass 'age for the heated air into the annular flue h n V .The operation; of the kilnis as follows: Assuming that the nateria l to be burned or are .l if i l pla ed pon h k ln Q andth'a't the kiln is col d, the air inlet danr 119. 1 nd 27 ar c ed, an h s uriae-see are 'mevdy dmit ng ld ai hqt, gase t et ring th f gli h e wa aredeflectedupwardlyby the bafiie walls 7. reflected from the domed roof 4 downwardly through the material on the kiln floor, pass through the vertical fiues 15 of the recuperator units and out through the header ll and flue 12 to the stack.

\Vhen the recuperator becomes sufiiciently heated to establish an ascending circulation through the air passages thereof, the dampers 27 and'27 controlling the air inlets 2G and 26 respectively are opened, and the controlling dampers 34 are inserted to close the air ports 35, thereby cutting oil the supply of cold air to the burners. The air now entering through the air inlets 26 and 26' of the recuperator units 10 and 10 passes back and forth through the several ascending stages of the horizontal passages 19 of the said recuperator units, and is distributed, at a high temperature, to the burners 5 by the annular flue 32 and the passages 33. Each of the recuperator units acts correspondingly, drawing in air through the inlets 26 and 26 and dischargingthe same into the annular flue 32 at substantially diametrically opposite points therein. By thus using the exhaust gases to heat the incoming air, the thermal cfliciency of the kiln is greatly increased over the present types of kilns ingeneraluse. In fact, the recuperative feature makes possible in a bee-hive kiln the use of temperatures as high as 8000 degrees Falnu, whereas in an ordinary downdraft bee-hive kiln without the described recuperative feature, it is impracticable to secure temperatures in excess of 2500 degrees Fahr. Thus the down-draft bee-hive kiln, the advantages of which are well known in the art, is rendered available for use at high temperatures, and more efficient at the ordinary temperatures at which such kilns have heretofore been used.

I am aware that various changes may be made in the described details of construction of the kiln, without in any manner changing or varying the described invention.

lVhile the particular form of construction herein described is believed to be the most practicable and efiicient for the work desired, still I do not wish to be understood as limiting or confining the invention thereto.

Having thus described the invention what is claimedas ncw and desired to be protected by Letters Patent is 1. Thecombination with a heating chamber, provided with openings in the floor thereof, of a recuperator situated immediately' beneath said floor, a plurality of vertical fiues in said recuperator having their upper ends in registry with the openings in the floor of said chamber, an exhaust flue in communication. with the lower ends of said flues, a plurality ofhorizontal passages in saidrecuperator independent from but adjacent to said vertical fines, and chambers with which the ends of said horizontal passages register connections between said chambers and the heating chamber so that air entering zontal passages for conducting air into said heating chamber, and a central vertical partition dividing the recuperator into two similar independent units symmetrically disposed with respect to the vertical axis of the entire structure.

3. The combination with a heating chamber, of a recuperator situated beneath the floor thereof, said recuperator having ver tical flues for conducting the exhaust gases out of said heating chamber, and adjacent independent horizontal passages for conducting air into said heating chamber, and said recuperator being divided by a central vertical partition into two similar independent units symmetrically disposed with respect to the vertical axis of the entire structure, said units having independent inlet and outlet openings communicating with said horizontal air passages.

4. The combination with a heating chamber having a plurality of burners symmetrically disposed in a horizontal plane about its periphery, a horizontal annular flue within the wall of said heating chamber, and passages connecting said annular flue with said burners, of a recuperator situated beneath the floor of said heating chamber, flues within the recuperator for conducting the exhaust gases away from said kiln, and passages adjacent to said flues for conducting air into said annular flue of said heating chamber, said recuperator being divided by a vertical central partition into two similar units symmetrically disposed with respect to the vertical axis of the entire structure, said lltt units having their respective air outlets into said annular flue at diametrically opposite points therein.

5. The combination with a recuperator having independent adjacent passages for relatively hot exhaust gases and relatively cold incoming air, of a heating chamber situated. above the recuperator, and communicating with the recuperator, a plurality of burners symmetrically disposed in a horizontal plane about the wall of said heating chamber, a horizontal annular flue within said wall, passages connecting said annular flue with said burners, air inlet ports within the kiln wall for supplying air to the burners, and slide dampers within said ports arranged to regulate the flow of air through said connecting passages.

6. The combination with a heating chamber having an opening in the floor thereof, a plurality of wing walls having vertically disposed apertures therebetween communicating with the openings in the floor of the heating chamber, of a recuperator having suitably disposed flues for conducting the relatively hot exhaust gases away from said chamber registering with the apertures between the wing walls, and a plurality of suitably disposed confined passages arranged adjacent the exhaust flues for conducting the relatively cool unburned gases to the heating chamber.

7. The combination with a heating chamber, of a recuperator having means for leading relatively hot exhaust gases from the chamber and relatively cold incoming air thereto, a plurality of burners disposed about the wall of the chamber, a flue around the recuperator and passages connecting the flue with the chamber, air ports leading to the connecting passages and dampers arranged within said ports, substantially as described.

8. The combination with a heating chamber having a plurality of wing walls with apertures therebetween, of a recuperator provided with suitably disposed passages for conducting the hot exhaust gases from the chamber in registry with the vertically disposed apertures between the wing walls below the recuperator and an independent inlet passage adjacent the exhaust passage for conducting relatively cool fluid in the tortuous direction into the heating chamber.

9. The combination of a heating chamber, provided with openings in the floor thereof, of a recuperator disposed within the said chamber, a plurality of vertically disposed flues in the recuperator having their upper ends in registry with the openings in the floor of the heating chamber, a plurality of wing walls having therebetween passages arranged at the lower end of said vertical fines and communicating therewith for leading the exhaust gases from the recuperator, and independent inlet passages adjacent the exhaust gases flues in said recuperator for supplying relatively cool air to the heating chamber.

10. The combination with a heating chamber provided with openings in the floor thereof, a recuperator situated beneath said chamber, a plurality of vertically disposed flues in said recuperator having their uppers in registry with the openings in the floor of the heating chamber, a plurality of wing walls, having passages therebetween arranged at the lower end of said vertical flues and in communication therewith for leading the exhaust gases from the recuperator, a plurality of horizontal passages in the recuperator arranged adjacent the vertical flues, but independent thereof, and

chambers with which the ends of said horizontal passages register so that air entering the lowermost of said horizontal passages is caused to pass upwardly in a substantially zig .zag direction before entering the heating chamber.

11. The combination with a heating chamber of a recuperator having flues for conducting the exhaust gases out of said chamber, adjacent fines for conducting air into said heating chamber, and a partition dividing the recuperator into two independent units symmetrically disposed with respect to the vertical axis of the entire structure.

recuperator into independent units, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ROBERT D. PIKE.

Witnesses:

N. A. AOKER, D. R. RICHARDS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, 7 Washington, D. G.

a heating chamber, of a recuperator havmg fines for 

